writing ALERT_EN and BUSY_ALERT to the chip config register clears
pending alerts, BUSY_ALERT is cleared when reading back the register
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>